In general, both consumers and flooring manufacturers are concerned with the negative impact of soiling on the appearance of floors and carpets. Carpet manufacturers take many steps to minimize the detractive appearance of soils on carpets through careful selection of fibers, soil release finishes, and colors which serve either to make soils easy to remove or hide their presence. Consumers have also employed means to minimize the effect of soiling on their floors and carpets by frequent vacuuming and sweeping to retrieve soils.
Another known means for preserving floor appearance is to trap soils before they are transferred via foot traffic onto permanent floors and carpets. This is typically done with the use of floor mats. To be totally functional, such floor mats need to effectively remove and retain both wet and dry soils, particularly when utilized at entry points from the outdoors.
In many instances, carpet remnants and carpet-like structures are utilized at such entry points and function well to remove dry soils from the shoe surface. However, to provide a satisfactory result, wet soils also need to be absorbed by such mats. The contact time during which this absorption takes place is often very short. Using a normal walking pace of about 100-120 steps per minute, this contact time is typically about 0.5 seconds. In such case, it is desirable that the floor mat have quick enough absorption rates that the wet soils can be absorbed from the bottom of a person's shoes during this short 0.5 second residence time.
Carpet remnants have not always proven totally effective in this regard. To a degree this may be due to the moisture resistant, i.e., hydrophobic, nature of the fibers utilized to manufacture the carpets from which they are cut and to moisture resistant treatments imparted to the carpets by the manufacturers. Furthermore, soils deposited on such carpet remnants are often readily visible, particularly on lighter colored materials, thereby necessitating disposal or at least cleaning of the carpet remnant due to an unsightly appearance long before its absorptive capacity has been reached. Although carpet remnants are relatively inexpensive since they are salvaged from scrap, carpet-like structures specifically manufactured for floor mat applications are typically quite high in cost due to the relatively high cost of the labor and materials required.
Accordingly, numerous efforts have been undertaken in the past to provide a disposable, low cost floor mat which will function effectively to remove and retain wet and dry soil, which will minimize the appearance of objectionable soil on the mat's surface in use, yet which is low enough in cost that it can be readily disposed of as soon as its soil loading capacity has been utilized.
Prior art disposable mat structures intended to remove dry soil are well known in the art. Typically these dry soil removal structures employ one or more substantially planar, adhesive surfaced sheets which serve to contact and secure particulate soils thereto when contacted by a shoe sole or other soiled object. In many instances, the individual adhesive sheets are stacked in multiple layers either directly on the floor surface or indirectly by means of a specially designed holder. Exemplary of such structures are those disclosed in U.S. Pat. No. 4,143,194 issued to Wihksne on Mar. 6, 1979; U.S. Pat. No. 3,785,102 issued to Amos on Jan. 15, 1974; U.S. Pat. No. 3,717,897 issued to Amos et al. on Feb. 27, 1973; and U.S. Pat. No. 3,083,393 issued to Nappi on Apr. 2, 1963. While these structures may work reasonably well for dry particulate soil removal and retention, they are non-absorptive and hence totally ineffective for the removal and retention of wet soil. Furthermore, since these prior art adhesive sheet type structures are substantially planar and relatively incompressible, there is little tendency for the mat structure to deform and allow complete contact with substantially all of the shoe's lowermost surface. Accordingly, only isolated portions of the shoe's lowermost surface are effectively cleaned by such mat structures. Finally, due to the fact that soils transferred from the shoe sole to the mat surface are readily visible because of the impermeable nature of the imperforate adhesive sheets, frequent removal of the uppermost layer and consequently greater cost is associated with the use of such disposable mat structures.
Combination cleansing and sanitizing mat structures are also known in the art. For example, U.S. Pat. No. 3,696,459 issued to Kucera et al. on Oct. 10, 1972 discloses an assembly which is provided with a first area which moistens the soles of the wearer's shoes by utilizing the wearer's weight to dispense a controlled amount of cleaning solution to loosen the dirt. An adjacent second area removes the cleaning solution along with the suspended dirt and dries the shoes. Still another sanitary door mat is disclosed in U.S. Pat. No. 2,282,672 issued to Nelson on May 12, 1942. Nelson discloses a structure in which a disinfectant reservoir is provided with an insert of absorptive material having sufficient mechanical resistivity to clean shoe soles. A liquid disinfectant is typically retained within the reservoir to treat the shoe soles during the soil transfer process. Such structures are, however, typically expensive thereby making the cost of disposal relatively high. Furthermore, the presence of liquid in the reservoirs of such structures makes installation and removal without spillage difficult.
A more recent attempt to reduce the cost of the mat structure and consequently reduce the cost associated with its disposal is disclosed in U.S. Pat. No. 4,328,275 issued to Vargo on May 4, 1982. Vargo discloses a disposable floor mat for use in bathrooms and the like comprising a sheet of liquid absorbent matting having raised portions for supporting a person's feet. These raised portions have a liquid-repellant coating thereon for maintaining the feet relatively dry as liquid falling onto the mat is absorbed by the matting. The raised portions are preferably comprised of cellulose fibers and starch and are characterized as being substantially incompressible. The primary purpose of the mat appears to be the absorption of spilled liquids.
U.S. Pat. No. 3,856,610 issued to Bruneel on Dec. 24, 1974 discloses a floor mat construction wherein an absorbent fibrous substrate is enclosed by a liquid impervious skin such as polyurethane which is adhered to the surface of the absorbent portion. The uppermost surface of the mat is substantially planar and is perforated by a plurality of aligned bores extending a predetermined depth into the absorbent body portion of the mat. The aligned bores are utilized for the absorption of liquid as well as to trap small particulate.
U.S. Pat. No. 3,517,407 issued Wyant on June 30, 1970 discloses a disposable mat made from a paper towel absorbent encapsulated on its lowermost and edge portions by means of a polyethylene sheet and protected on its uppermost surface by means of a woven craft paper yarn to provide abrasion resistance.
Despite the appearance of the aforementioned prior art structures in the patent literature, none of the disclosed embodiments appear to have gained widespread commercial acceptance. It is believed that this is due to the relatively high cost associated with disposal after a relatively short use life, the inability of such structures to effectively remove and retain both dry particulate and wet soil and the unsightly appearance which rapidly develops shortly after these prior art mat structures are placed in service.
Accordingly it is an object of the present invention to provide a low cost disposable absorbent structure which will effectively remove and retain both dry particulate and wet soil from a soiled object coming in contact therewith.
It is a further object of the present invention to provide a structure having a resiliently deformable, macroscopically patterned, three-dimensional, object contacting surface which will deform substantially when contacted by a soiled object to maximize the overall degree of contact with the object, yet which will not collapse into a single plane so as to permit redeposition of transferred soils back onto the object being cleansed when subjected to normal standing or walking pressures.
It is a further object of the present invention to provide, in a particularly preferred embodiment, a structure wherein the bulk of the soils transferred from the soiled object are entrapped and/or absorbed into an absorbent substrate located subjacent the object contacting layer rather than remaining completely visible on the object contacting surface of the structure.
It is a further object of the present invention to provide such a structure wherein the soils transferred from the soiled object are not redeposited onto the surfaces of cleansed objects coming in contact with the object contacting surface of the structure.
Finally, it is an object of the present invention to provide such a structure wherein under normal use conditions, substantially all of the soil storage capacity of the structure may be utilized prior to its disposal without the appearance of said structure becoming objectionable.